1. Field of the Invention
This invention relates to a position adjusting device attached to an ophthalmologic measuring instrument to adjust the position of various ophthalmologic measuring instruments with respect to an eye to be examined.
2. Description of the Prior Art
In an ophthalmologic measuring instrument such as a refractomenter or an ophthalmometer, it is necessary to accurately adjust the position of the measuring device with respect to an eye to be examined in order to enhance the measurement accuracy and various devices have been proposed for such purpose. As a simple device, there is known one in which a certain pattern is projected upon the eye to be examined and the image of such pattern by the cornea of the eye is observed, but when the environment of the eye to be examined is dark, accurate position adjustment has been difficult to do. There is also known an automatic follow-up device in which the movement of the eye to be examined is photoelectrically detected to cause the measuring device to automatically follow said movement, or a device using infrared rays, but these have been considerably complicated and of large-scale construction and have been disadvantageous for making the entire measuring device compact.